Call failure signaling arrangement



March 29, 1949. JOEL, JR 2,465,539

CALL FAILURE SIGNALING ARRANGEMENT v I Filed Dec. 20, 1946 3 Sheets-Sheet 1 /NVENTO/? A.EJOL,JR. BY

A 7' TOPNEV March 29, 1949. A. E. JOEL, JR 2,465,539

CALL FAILURE SIGNALING ARRANGEMENT Filed Dec. 20, 1946 3 sheetsesheet 2 SW/ TCHES INCOH/NG TRUNK CONN TO INTERRUPTfR FRAME CC):

TO RING/N6 MACH/NE //v NTOR A. E. JOEL, JR.

A 7' TVORNEP March 29, 1949.

Filed Dec. 20, 1945 TO RELEASE am. can 364 5 Sheets-Sheet 3 MARKER lNl/ENTOR A. E. JOEL JR.

A T TORNEV Patented Mar. 29, 1949 UNITED STATES PATENT OFFICE 2,465,539 CALL FAILURE SIGNALING ARRANGEMENT Amos E. Joel, In, New York,

Bell Telephone Laboratories,

N. Y., assignor to Incorporated,

New York, N. Y., a corporation of New York Application December 20, 1946, Serial No. 717,519

ers which receive the information required for their operation from register senders. In general, two types of senders and markers are employed. At the originating omce, the register sender receives the complete ofiice and numerical designation of the wanted line by means of dial pulses, transmits the oifice designation to the originating marker which sets up the connection to the wanted ofiice, and transmits the numerical desig nation to a terminating sender by means of revertive pulses. At the terminating ofilce the function of the sender is chiefly to control a. marker which controls the completion of the connection to the called line.

This arrangement presents a problem where ofiices employing step-by-step switches are employed in the same area, since special means must be provided either for receiving dial pulses in connection with the terminating equipment at the cross-bar office, or for transmitting revertive pulses at the step-by-step ofiice. Where there are only a limited number of trunks connecting such offices, one simple solution of the problem is to provide a set of simple registers for each such trunk.

The present invention concerns such an arrangement and more specifically is concerned with means for transmitting a trouble signal to the originating ofice when the call cannot be handled at the terminating omce.

One feature of the invention lies in means for transmitting an overflow signal from the individual register circuit when no marker can be reached.

Another feature lies in providing register releasing means which is efiective to transmit an overflow signal over the incoming trunk.

In addition the register releasing means is also provided with means for maintaining the battery supply to the incoming trunk during the transmission of the overflow signal.

A clearer understanding of the invention may be obtained from a consideration of the following description in connection with the drawings in which:

Figs. 1 and 2 show a trunk circuit incoming from a distant oflice;

Fig. 3 shows a register circuit individual to the trunk circuit of Figs. 1 and 2; and I Fig. 4 shows the proper arrangement of Figs. 1 to 3, inclusive.

The trunk and register circuits of the present disclosure are particularly adapted to be used in a telephone oflice employing cross-bar switches for the purpose of completing calls originated at an office employing step-by-step switches. In the establishment of such an interoffice connection certain of the digits dialed by the calling subscriber are used in establishing the connection to the office at which the wanted line terminates,

while the remaining digits are transmitted directly to the terminating offlce for use there in selecting the called line and extending the incoming trunk thereto. Such a trunk and register would likewise serve for the completion of calls from any office from which the number of the wanted subscriber is transmitted by dial type pulses.

When a subscriber at nates a call, his substation I00 is associated with the equipment at that ofiice, indicated at ml, which responds to the dialing of the proper office code to connect the calling line with an idle trunk leading to the wanted office, where it terminates in a pair of trunk conductors such as I02 and I03.

When this connection has been established, a circuit is completed from battery through the lower winding of relay I06, conductor I I9, contact I of relay I05, contact I of relay I04, conductor I02, through the equipment IOI at the originating ofice to the bridge supplied by that equipment or by the subscriber's line and back to conductor I03, contact 6 of relay I04, contact 4 of relay I05, conductor IZI to ground through the upper winding of relay I06. Relay I06 operates in this circuit, closing an obvious circuit for relay I01, which operates to prepare a pulsing path to the register circuit of Fig. 3, supplies ground over contact 4 to conductor I08 to mark thetrunk busy to the test circuit, and at contact 5 extends ground from contact I4 of relay I09 to conductor IIO to provide locking ground for relays of the register circuit.

When dial pulses are received from the originating office, relay I06 releases and reoperates in response to each pulse. Relay I01, being slow to release, remains operated. Each time that relay I06 releases, it closes a pulsing circuit leading to the register circuit by connecting ground over its back contact, contact I of relay I01, and contact I3 of relay I09 to conductor III. In the register circuit, conductor III extends over contact 5 of relay 300, over normal contact 341 of register the distant oflice origi- 5 nector 253 to permit the marker to connect with this trunk. Relay 20I at contacts 6 and 5, 9 and I and I2 and I3 transfers the tip, ring and sleeve conductors 203, 204 and 205 from the trunk circuit to conductors leading to the trunk connector 253 to permit the marker to test the connection through the terminating switches 252 when it has been established. In addition, at contacts 2 and 1 it grounds conductors H0 and 2" to prepare the terminating switches for operation.

With relay 20I operated, relays 206, 201 and '208 are connected over contacts 3, II and 4 to conductors '2II, 2I6 and 2I2 and through the trunk connector 253 to the marker for selective operation to determine the ringing or other signaling current to be employed.

Relay 206 is operated whenever ringing current is to be transmitted to the called line and normally connects the ringing source to the ring conductor. If the called number represents the tip party on a two-party line, relay 208 will be operated to cause the ringing source to be connected to the tip conductor. If the connection cannot be completed, relay 201 will be operated in combination with relay 208 if the called line is busy and in combination with both relays 206 and 208 if there are no channels available over which to reach an idle line. If the called line is a line for which no charge is made relays 201 and 206 are operated. Relay 201, when operated, locks directly to conductor 2 I8 which is grounded as described hereinafter, while relays 206 and 208 lock over the back contact of relay 209 to the same conductor.

After the marker has completed its functions and is ready to release, it connects ground to conductor 363, completing a circuit over the lowermost contact of relay 303, conductor 364, through the winding of relay I09 to battery. Relay I09 locks over its contact 8 to ground at contact 2 of relay I01. This locking ground is a signal to the marker that the transmission circuit has been closed through the trunk.

Relay I09 in operating at contacts 3 and I2 closes the incoming tip and ring conductors H9 and I 2| to condensers I23 and I24 to establish the talking circuit. At contact I6 it connects ground to conductor 2I8 to hold the ringing control relays operated after the release of relay 20I opens their operating circuits. At contact 6, relay I09 connects ground over conductor II2 to resistance 2 I 9. At contact I3 relay I09 opens the pulsing circuit and at contact I4 disconnects ground from conductor IIO, thereby opening one holding circuit for the register circuit.

At contact I5, relay I09 closes a release circuit for the register circuit. This circuit may be traced from ground, contact I5 of relay I09, conductor II3, over off-normal contacts 3| 3, 323 or 333 to the left winding of relay 300 and battery. Relay 300 operates, locking over its contact I0 to ground over ofi-normal contact 343 and through its right winding and contact 8 to ground supplied to conductor II 0 by the marker connector. At contact 9 relay 300 opens the start and holding circuits for the marker connector, previously traced to conductors 36I and 360. The opening of these circuits causes the marker to remove battery from conductor 362, thereby releasing relays 303 and 20I. The release of the marker and marker connector disconnects ground from conductor IIO.

When relay 303 releases, a circuit is closed from battery through the winding of relay was.

304, back contact of relay 303, contact 6 of relay 300, conductor 365, contact 8 of relay I04, conductor lI 4, contact I0 of relay 300 to ground over off-normal contact 343. A parallel circuit extends from conductor II4 over oil-normal contacts 3| 3, 323 and 333 to ground on conductor I I3 so that relays 300 and 304 remain operated until all of the registers have restored to normal. In addition relay 300 looks through its right winding and contact 8, contact 3 of relay 304, to ground at contact I I of relay 300. At contact 5 relay 300 opens the circuit of relay 302 and the operating magnets of the registers. At contact I4 relay 300 extends ground from conductor II3 to conductor 366 to prepare for sounding an alarm if the restoration of the registers is unduly delayed.

With relays 300 and 304 operated, circuits are closed for operating the release magnets 3I5, 325, 335 and 345. These circuits extend from ground over contact I2 of relay 300, contacts 4 and 6 of relay 304 to the windings of release magnets 3I5 and 335 and battery, and from ground over con tact I3 of relay 300, contacts 5 and I of relay 304 to the windings of release magnets 325 and 345 and battery.

When all of the registers are normal, the circuits for relay 304 are opened and that relay releases, in turn releasing relay 300, thereby restoring the register circuit to normal.

In the trunk circuit, the release of relay 20I restores the connection of the tip and ring conductors to conductors 203 and 204 leading through the terminating switches 252 to the called line 200. At contact I2, relay 20I connects ground through resistance 2I9 to the sleeve conductor 205 to hold the switch magnets operated. The closure of the tip and ring conductors establishes the circuit for signaling the called subscriber. Assuming that line 200 is an individual line, relay 206 will be operated alone and the ringing circuit will extend from the ringing source over conductor 220, contact 8 of relay 206, winding of relay 209, contact I of relay 201, contact I of relay 208, contact 9 of relay 206, contact 9 of relay 20L over the ring conductor 204 through the terminating switches 252 to the ringer at the called substation, back through the terminating switches 252 to tip conductor 203, contact 6 of relay 20I, contact 2 of relay 2%, contact I of relay 208, to ground over conductor 22 I.

When the called subscriber answers, relay 209 operates, opening the locking circuit for relay 206 which releases, removing ringing current from the called line. With relay 206 released, the tip and ring conductors from the called line are extended to the condensers I23 and I24 and to the windings of relay I I5 which operates, closing a circuit from ground over its upper contact, contact I of relay I09, conductor H6, contact 5 of relay 201, conductor 222 to the winding of relay I05, which operates and reverses the connection of battery and ground through the windings of relay I06 to the incoming tip and ring conductors I02 and I 03 as a signal that the called line has answered. Battery is now connected through the lower winding of relay I06, conductor H0, over contacts 3 and 5 of relay I 09, conductor I 20, contact 3 of relay I05 and contact 6 of relay I04 to the ring conductor I 03, while ground is connected through the upper winding of relay I06, conductor I2l, contacts II and I2 of relay I09, conduc tor I22, contact 2 of relay I05 and contact I of relay I04 to the tip conductor I02.

When the calling subscriber disconnects, the equipment at the originating ofiice IOI releases,

grass opening the circuit of relay I06 which in turn releases, followed after an interval by relay ItI. Re; lay III'I opens th locking circuit of relay I09 which also releases. Relay I09 releases relay Hi5, thereby restoring the connectionof relay I66 to the incoming trunk. At contact 6 relay I539 disconnects ground from conductor H2, but, since conductors II! and II2 are normally connected together in the timing circuit, the terminating switches 252 are held operated under'the control of relay I I which is held operated over the called line. When the called line disconnects, relay II5 releases, removing ground from conductor II2 and permitting the switches to restore.

With relay I09 released and relay I I5 operated,

ground is connected over the upper contact of relay H5, contact 2 of relay I09 and conductor H8 to start a timing operation in the timing circuit, at the end of which conductor I I! is disconnected from conductor I I 2 and the terminating switches release, in turn. releasing relay H5. If the marker is unable to complete the connection, because the called line is busy, it operates relays 281 and 208, and releases, operating relay I09 as above-described. When relay I89 operates, interrupted ground on conductor 226 is extended over contact 3 of relay 2%, contact Sci relay 2B8, contact 4 of relay 29'! to conductor 222 and the winding of relay I05, causing that relay to operate intermittently to reverse the connection of relay IIIB to the trunk circuit as a busy signal to any operator whose position may have been included in the incoming connection. At the same time, tone on conductor 225 is connected over contact 3 of relay 201, contact I of relay 2%, through condenser 22?, contactfl of relay 2% and over contact 3 of relay I69 to conductor H9 and thence to the calling subscribers line. I I

If the marker cannot complete the connection because no path is available to the wanted line, itoperates relay 2% as well as relays 28? and 2513 and interrupted ground of a difierent rate and a difierent tone, are supplied over conductors 223 and 226 as an overflow signal.

In the case of trouble in the marker, a trouble release signal is given to the register circuit and the overflow signal is supplied by that circuit. In the case of trouble, either in the marker con nector or the marker, none of the trunk relays I09, 2G6, 201 and 268 is operated by the marker, but ground is connected to conductor 367, operating relay 3% through its right winding. Relay 3B0 locks to conductor I It) and operates relay 304 to restore the registers to normal as above ,described. In addition, since relay I99 has not been operated, a circuit is closed from interrupted ground on conductor 359 over contact 3 of relay 309, conductor 318, contact III of relay IE9 to con ductor 222, winding of relay I05 and battery, operating relay I05 intermittently at the overflow rate. With relay I09 not operated, the connec.- tions from the windings of relay IEIE over conductors H9, I2Il, I2I and I22 to the front contacts of relay I95 are opened. In order to as sure a proper reverse battery signal and to prevent premature release of the incoming trunk, relay 306, at contact I connects conductor M9 to conductor I20 and, at contact z connectscone,

ductor I2I to conductor I22. At contact 4 ay; v

' sourca-o ifiisc lipg.currentm der the centra 30Dconnects overflowi tone on conductor 368,1 6 er conductorffillgcontact 4 ofrelay' I tor IIQQandtIience' qonduqtop I2 ll vt f upply 3 0V 991" "If the'call is ab 11 pleted, with one or more: of the registers 3m t9 340 011 normal, therelease of relay I06 followed by the release of relay IIIfI closes a circuit from ground at contact 6 of relay IIII, over conductor I-I3 and the closed off-Inormalcontacts 3I3, etc., tothe left winding of relayBIJII to restore the registers to normal as described.

If the trunk is reseized from the originating oi fice before the called subscriber disconnects and the timing circuit releases the terminating twitches, the number of the wantedline maybe recorded and the marker start its functions When the marker operates relay I, that relay disconnects the ground supplied by relay H5 through resistance 2 I 9, irom the sleeve conductor 265 leading to the terminating switches 252 there-,- by releasing the switches andpreparing them for reoperation to connect with the new called line.

What is claimed is; r I a 1. In a telephone system, trunk circuits, regis tersindividual to each of said trunk circuits, means ior setting said registers from said trunk, switches for completing connections from said trunk circuits, control circuits common to said trunks for controlling the operation of said switches, a source of signaling current, means re spcnsive to the operation of the registers in:

dividua-l. to a trunk to connect said registerswith one of said control circuits, means operated by said control circuit for connecting said trunk with said source of signaling current if said control circuit fails to complete a connection from said trunk and auxiliary means associated with said 1 registers for connecting said trunk with said source of signaling current if said registers cannot be connected with a control. circuit. 2. In a telephone system, trunk circuits, regis; ters individual to each of said trunk circuits, means for setting said registers from said trunk, switches for completing connections from said trunk circuits, control circuits common to said trunks for controlling the operation of said switches, a source of signaling current, a connector reseponsive to the operation of the registers individualto a trunk to connect said registers with one of said control circuits, means operated by said control circuit for connecting said trunk with said source of signaling current if said control circuit fails to complete a connection from said trunk and auxiliary means associated with said registers for connecting said trunk with said source of signaling current under the con trol of said connector if said connector cannot connect said registers with a control circuit.

3. In a telephone system, trunk circuits, regis ters individual to each of said trunk circuits, means forsetting said register from said trunk, switches for completing connections from said trunk circuits, control circuits common to said trunks for controlling the, operation of said switches, a source of signaling current, a con; nectorresponsive to the operation of the registers individual to a trunktoconnect said registers with one of said control circuits,;means operated by said contrclcircuit for connecting said trunk with said source of signaling current iisaid con; trol circuit failsto complete a connection from sa d nk anwu e m a a s ted w h. sar r isters senaeetinaseisl.trunk Wi h aid:

i th i1; grit y. registers in ividual to each d trunk circuits, means for setting said registers from said trunk, switches for completing connections from said trunk circuits, control circuits common to said trunks for controlling the operation of said Switches, a source of signaling current, a connector responsive to the operation of the registers individual to a trunk to connect said registers with one of said control circuits, a relay operated by said control circuit on a successful call to complete a talking circuit through said trunk, means controlled by said relay for restoring said registers, means operated by said control circuit for connecting said trunk with said source of signaling current if said control circuit fails to complete a connection from said trunk and auxiliary means associated with said register restoring means for connecting said trunk with said source of signaling current if said connector cannot connect said registers with a control circuit.

5. In a telephone system, trunk circuits, talking circuits to be completed, through said trunk circuit, registers individual to each of said trunk circuits, means for setting said registers from said trunk, switches for completing connections from said trunk circuits, control circuits common to i said trunks for controlling the operation of said switches, a source of signaling current, a connector responsive to the operation of the registers individual to a trunk to connect said registers with one of said control circuits, a relay op.- erated by said control circuit on a successful call to complete a talking circuit through said trunk, means controlled by said relay for restoring said registers, means operated by said control circuit for connecting said trunk with said source of signaling current if said control circuit fails to complete a connection from said trunk, auxiliary means associated with said register restoring means for connecting said trunk with said source of signaling current if said connector cannot connect said registers with a control circuit a battery supply, normally closed circuits for connecting said battery supply to said trunk, means under the control of said signaling current for interrupting said normally closed circuits and means for closing supplementary circuits for maintaining the connection of said battery supply to said trunk while said signaling current is connected therewith.

6. In a telephone system, trunk circuits, talking circuits to be completed through said trunk circuit, registers individual to each of said trunk circuits, means for setting said registers from said trunk, switches for completing connections from said trunk circuits, control circuits common to said trunks for controlling the operation of said switches, a source of signaling current, a connector responsive to the operation of the registers individual to a trunk to connect said registers with one of said control circuits, a relay operated by said control circuit on a successful call to complete a talking circuit through said trunk, means controlled by said relay for restoring said registers, means operated by said control circuit for operating said relay and connecting said trunk with said source of signaling current if said control circuit fails to complete a connection from said trunk, auxiliary means associated with said register restoring means for connecting said trunk with said source of signaling current if said connector cannot connect said registers with a control circuit a battery supply, normally closed circuits for connecting said battery supply to said trunk, means under the control of said signaling current for interrupting said normally closed circuits and means under the control of said relay or under the control of said register restoring means for closing supplementary circuits for maintaining the connection of said battery supplyto said trunk while said signaling current is connected therewith.

7. In a telephone system, trunk circuits, talking circuits to be completed through said trunk circuit, registers individual to each of said trunk circuits, means for setting said registers from sald trunk, switches for completing connections from said trunk circuits, control circuits common to said trunks for controlling the operation of said switches, a source of signaling current, a conters, means operated by said control circuit for.

operating said relay and connecting said trunk with said source of signaling current if said control circuit fails to complete a connection from said trunk, auxiliary means associated with said register restoring means for connecting said trunk with said source of signaling current if said connector cannot connect said registers with a control circuit, a battery supply, normally closed circuits for connecting said battery supply to said trunk, means under the control of said signaling,

current for interrupting said normally closed circuits and means under the control ofsaid relay or under the control of said register restoring means independent of one another for closing supplementary circuits for maintaining the connection of said battery supply to said trunk while said signaling current is connected therewith.

8. In a telephone system, trunk circuits having incoming and outgoing conductors, registers individual to each of said trunk circuits, means for setting said registers over said incoming conductors, switches for completing connections from said outgoing conductors, control circuits common to said trunk circuits for controlling the operation of said switches, a connector responsive to the operation of the registers individual to a trunk to connect said registers with one of said control circuits, a first relay in said trunk operated by said control circuit on a successful call to connect said incoming and outgoing conductors into a talking circuit, a reversing relay, means operated by said control circuit for intermittently operating said reversing relay if said control circuit fails to complete a connection from said trunk, 21. release relay associated with said register, means normally under the control of said first relay to operate said release relay to restore said registers, means under the control of said connector for operating said release relay if said connector fails to connect a control circuit with said registers, and means under the control of said release relay to intermittently operate said reversing relay.

9. In a telephone system, trunk circuits having incoming and outgoing conductors, registers individual to each of said trunk circuits, means for setting said registers over said incoming conductors, switches for completing connections from said outgoing conductors, control circuits common to said trunk circuits for controlling the operation of said switches, a connector responsive to the operation of the registers individual to a trunk to connect said registers with one of said control circuits, a first relay in said trunk operated by said control circuit on a successful call to connect eeeegee seid ie emiee 945E1- i feine eeesl etgr n cite it e revers ng el x battery and g blind co eeqte i t9 n m ng cqnqluc ors se fld' vere ne relay is @e n reizedr ollfatel by s d coli el cirquit tor in ermi y operating said reversing relay if said control cir- 011it fails to m let a. qem ectiqn f om said u n ac s n s id fi t el y o maint ining t om' o tt y and gr u d with seid. indofiiing n uct rs hen sa dv versi r y e 'ed eur l ese r lay. s o ia ed; w t sen registers, m ans ne mel y der the qntr l of. se fi re ay to Qnerete sai release relay to restore said registers, means under the control of; said co eet lrpera ng, sa d re se. relay i saicl connector fails :to qongeqt a control circuits w th Said eg s s. mean nde e c n r l of id l a e re ayw termitte t y r t id reversing, e a a d eqnjtws on, e dm e e. elay r iniee t e. eennecti n oi ba te y and, e o i fd w said e m ne. mi luctor en. said; e s n l y s. oper tedte ephqee s st mlt unk c xeu tsh n e incoming z q outgoing cq q ugtors, registers ind v a e h i. said trunk ir u ts, m an o ett aid, eg sters over aid inQQmin conduetors, switches for completing connect ns f om se cl outs, pg, c ndu ors. on rol circuits cpmrrion to sa i ti mik circuits for; con-h We e rae fi en r aiQ wit heee mil timev responsive t he qpexet qe Qf he e i ters v u m a 2mph o rqonneet seict e st rs w h a ;o1;qi u.i fi st. r lay in said; t m s op eem sale; en re! ircuit 1 e suer.

cess ul ce l eennnectseie inaominglend outepine conduct rs into a telkinegcimuit, a rev rsing relax. battery and ground connected tosaid incoming eonductoxs lien said eversing relay isde ner= gized, means operated by, said ,control circuit for nte mitte tl v operatin said reversin yf said control eircuitfails to complete aconnection from said'trunk, contacts on said first, relay io: maintaining the. connection, of battery and ground with saidincoming Conductors whensaid reversing relay. isoperated, a. releaserela,y-. associeted with said. registers, means normally, unde the control of, said firstrelay to operate said release relay-to restoresaid registers, means under the control ofsaid. connector for peratingsem release relay, said cQnnectorz fails to connect a; central circuit.- with said, registers, means under; the control, of said release relay to intermittentlg operate said reversing relay and \contacts on salt; release relay; to: maintaining theconnecbiqnof battery anci g oundrwttn said-incoming conductors; ingepenq nt of, said first rela when'said. reversing; relay is ope eted j- JQ REFERENCES? crren The following reterenees a -e; ofixtecordr in the 

